Police are investigating a hit-and-run crash north of Adelaide overnight, which has seriously injured a motorcyclist.
Emergency services were called to the Thiele Highway at Freeling at about 6pm, after reports of a ute towing a trailer colliding with a motorcycle.
Police say the male driver of the light-coloured ute got out of the vehicle and spoke to witnesses before driving off, leaving the trailer behind.
Police are searching for a man in his late teens or early 20s, with a slim build, short dark-coloured hair and wearing a light-coloured jacket, a dark-coloured T-shirt and light-coloured pants.
The tray-top ute, which did not have sides, would have damage to its left side.
Senior Constable Matt Brown urged people who saw the ute to call police or Crime Stoppers.
"Just take details of the driver or people that are with it, and the registration number as well, because that's one thing that we're missing at the moment," he said.
The Thiele Highway has reopened after earlier being closed between Job and Wandel roads.
